Climate Change

[davieddy]

Originally Posted by cheesehead

I apologize for the

dirty fork?

[__HRB__]

Originally Posted by davieddy

dirty fork?

Be careful - asking for this could trigger akruppa the apoplectic Hun's policing desire and get your donkey banned faster than you can say 'fork him'!

[Brian-E]

Originally Posted by davieddy

dirty fork?

Breathe heavily on it, wipe it on your penguin suit, and replace it on the table.

[davieddy]

Originally Posted by Brian-E

Breathe heavily on it, wipe it on your penguin suit, and replace it on the table.

Nah. Waste not, want not. Think me have another slice of
Christmas Pizza.

[__HRB__]

Global Warming - Conspiracy Theory - Jesse Ventura

http://www.youtube.com/watch?v=igg79pqfT08
http://www.youtube.com/watch?v=_YCR9tClX8I
http://www.youtube.com/watch?v=A_3arkEld7I
http://www.youtube.com/watch?v=CX-GmtqgQJ0

~40 minutes + grain(salt) - drama^2 = insight

[cheesehead]

Originally Posted by ewmayer

It is interesting, though, that you've repeatedly touted the "multiple independent lines of evidence for man-made global warming"

Originally Posted by mdettweiler

when asked to produce evidence to show that human-produced CO₂ is responsible for that amount of warming, you refer me to the models

From http://www.skepticalscience.com/What...l-warming.html,

Humans are emitting CO2 at such rates that atmospheric CO2 is at its highest level over the past 800,000 years (Brook 2008). The rate of increase is the fastest in 22,000 years (Joos 2008)

Satellites measure less infrared radiation escaping out to space at the wavelengths that CO2 absorb energy (Harries 2001, Griggs 2004, Chen 2007)

Surface measurements find more infrared radiation returning back to the Earth's surface (Philipona 2004), specifically at the wavelengths that CO2 absorb energy (Evans 2006)

. . .

Cooling and contraction of the upper atmosphere consistent with predicted effects of increasing greenhouse gases (Lastovicka 2008)

(to be continued)

[cheesehead]

From http://www.skepticalscience.com/empi...al-warming.htm,

The line of evidence that humans are causing global warming is as follows:
http://www.skepticalscience.com/imag..._flowchart.gif

( Image text: We're raising CO2 levels --> CO2 traps heat --> Our planet is accumulating heat )


Humans are raising CO2 levels

. . .

What we observe is that in pre-industrial times over the last 10,000 years, CO2 was relatively stable at around 275 to 285 ppm. Over the last 250 years, atmospheric CO2 levels have increased by about 100ppm. Currently, the amount of CO2 in the atmosphere is increasing by 15 gigatonnes every year.

[Here, there's a graph: Figure 1: CO2 levels (parts per million) over the past 10,000 years.]

Global CO2 emissions are derived from international energy statistics, tabulating coal, brown coal, peat, and crude oil production by nation and year. This means we can calculate how much CO2 we're emitting not only in recent years, using United Nations data, but also estimate fossil fuel CO2 emissions back to 1751 using historical energy statistics. What we've found is fossil fuel and cement emissions have continued to increase, climbing to the rate of 29 Gigatonnes of CO2 per year in 2008.

[Here, there's a graph: Figure 2: Total Global Carbon Emission Estimates, 1750 to 2006]

In other words, humans are emitting nearly twice as much CO2 than what ends up staying there. Nature is reducing our impact on climate by absorbing a large chunk of our CO2 emissions. The amount of human CO2 left in the air, called the "airborne fraction", has hovered around 55% since 1958.

Further confirmation that rising CO2 levels are due to human activity come by analysing the types of CO2 found in the air. The carbon atom has several different isotopes (ie - different number of neutrons). Carbon 12 has 6 neutrons, carbon 13 has 7 neutrons. Plants have a lower C13/C12 ratio than in the atmosphere. If rising atmospheric CO2 comes fossil fuels[sic], the C13/C12 should be falling. Indeed this is what is occuring (Ghosh 2003) and the trend correlates with the trend in global emissions.

[Here, there's a graph: Figure 3: Annual global CO2 emissions from fossil fuel burning and cement manufacture in GtC yr–1 (black), annual averages of the 13C/12C ratio measured in atmospheric CO2 at Mauna Loa from 1981 to 2002 (red).]

CO2 traps heat

According to laboratory measurements and radiative physics, we expect that increasing atmospheric CO2 should absorb more longwave radiation as it escapes back out to space. In 1970, NASA launched the IRIS satellite measuring infrared spectra. In 1996, the Japanese Space Agency launched the IMG satellite which recorded similar observations. Harries 2001 compared both sets of data to discern any changes in outgoing radiation over the 26 year period. The resultant change in outgoing radiation was as follows:

[Here, there's a graph: Figure 4: Change in spectrum from 1970 to 1996 due to trace gases. 'Brightness temperature' indicates equivalent blackbody temperature (Harries 2001).]

What they found was a drop in outgoing radiation at the wavelength bands that greenhouse gases such as CO2 and methane (CH4) absorb energy. The change in outgoing radiation over CO2 bands was consistent with theoretical expectations. Thus the paper found "direct experimental evidence for a significant increase in the Earth's greenhouse effect".

This result has been confirmed by subsequent papers using the latest satellite data. Griggs 2004 compares the 1970 and 1997 spectra with additional satellite data from the NASA AIRS satellite launched in 2003. Chen 2007 extends this analysis to 2006 using data from the AURA satellite launched in 2004. Both papers found the observed differences in CO2 bands matched the expected changes based on rising CO2 levels. Thus we have empirical evidence that increased CO2 is preventing longwave radiation from escaping out to space.

What happens to longwave radiation that gets absorbed by greenhouse gases? The energy heats the atmosphere which in turn re-radiates longwave radiation. This re-radiated energy goes in all directions. Some of it makes its way back to the surface of the earth. Hence we expect to find increasing downward longwave radiation as CO2 levels increase.

Philipona 2004 finds that this is indeed the case - that downward longwave radiation is increasing due to an enhanced greenhouse effect. Evans 2006 takes this analysis further. By analysing high resolution spectral data, the increase in downward radiation can be quantitatively attributed to each of several anthropogenic gases. The results lead the authors to conclude that "this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming."

The planet is accumulating heat

Both of you have conceded this third point, but I'll quote a bit anyway:

When the planet is in energy imbalance, the whole climate system accumulates heat. The atmosphere warms. Oceans accumulate energy. Land absorbs energy and ice absorbs heat to melt. Murphy 2009 which adds up heat content from the ocean, atmosphere, land and ice. To calculate the Earth's total heat content, the authors used data of ocean heat content from the upper 700 metres. They included heat content from deeper waters down to 3000 metres depth. They computed atmospheric heat content using the surface temperature record and the heat capacity of the troposphere. Land and ice heat content (eg - the energy required to melt ice) were also included.

[Here, there's a graph: Figure 1: Total Earth Heat Content from 1950 (Murphy 2009). Ocean data taken from Domingues et al 2008.]

Figure 1 shows that the planet is accumulating heat at a rate of 190,260 GigaWatts. Considering a typical nuclear power plant has an output of 1 GigaWatt, imagine 190,000 nuclear power plants pouring their energy output directly into our oceans.

We also observe the heat capacity of the land and atmosphere are small compared to the ocean (the tiny brown sliver of "land + atmosphere" also includes the heat absorbed to melt ice). Hence, relatively small exchanges of heat between the atmosphere and ocean can cause significant changes in surface temperature. For example, in 1998, an abnormally strong El Nino caused heat transfer from the Pacific Ocean to the atmosphere. Consequently, we experienced above average surface temperatures. Conversely, the last few years have seen moderate La Nina conditions which had a cooling effect on global temperatures. And the last few months have swung back to warmer El Nino conditions. This has coincided with the warmest June-August sea surface temperatures on record. This internal variation where heat is shuffled around our climate is the reason why surface temperature is such a noisy signal.

. . .

So we see multiple lines of evidence that humans are causing global warming. Human CO2 emissions far outstrip the rise in CO2 levels, which is confirmed by the trend in carbon isotope ratios. The warming effect of CO2 is confirmed by satellite measurements of outgoing radiation and surface observations of downward radiation. The planet's energy imbalance is confirmed by ocean heat measurements and summations of the planet's total heat content.

[mdettweiler]

cheesehead,

My apologies for not getting back to this thread sooner. I'm afraid I haven't had much time lately for the rather time-intensive task of writing long rebuttal posts about once every day.

I've now read over all your posts since my most recent one before this, and while I still don't think you've answered the real question here (of how much actual temperature increase is going to be caused by global warming), I don't really have time to continue following up on this, so I'll let you go this time. If I had more time, I'd gladly continue this discussion, because even though neither you or I are likely to convince the other of our respective positions, it's always good to have lively public debate to provoke thought about this. Perhaps I can come back and pick up the line of discussion at a later date.

As for our PM discussion of science vs. non-science, that one ran into a similar sort of problem a while back. Again, I do hope to pick it up again at a later date.

Max

[cheesehead]

Originally Posted by mdettweiler

I still don't think you've answered the real question here (of how much actual temperature increase is going to be caused by global warming)

That question has already been answered by the estimates presented earlier.

Your claim that "how much actual temperature increase is going to be caused by global warming" is "the real question" that I haven't yet answered is only a rhetorical strawman device.

Speaking of unanswered questions, why do you keep dodging the questions I've put to you? Let's see some answers from your side!

so I'll let you go this time.

Bull.

This is just a pretense that I've dodged something, whereas the truth is that you're the one who hasn't answered important questions I've posed in this thread.

If I had more time, I'd gladly continue this discussion,

If you spent less time composing rhetorical trickery and more time giving us straight answers to straight questions, you'd be more respected.

because even though neither you or I are likely to convince the other of our respective positions,

You could convince me of your position ... if you'd present actual evidence to support your claims. But you don't, despite my repeatedly reminding you of that lack.

Instead of presenting evidence, you present only rhetoric. You are an intellectual coward. (I'm qualified to make that accusation because I behaved that way in certain situations when I was younger, so I recognize it when you do it now.)

As for our PM discussion of science vs. non-science, that one ran into a similar sort of problem a while back.

Yes, it did, didn't it?

I requested that you present legitimate criteria for distinguishing science from non-science, but you kept trying to pretend that thinly-disguised attempts to sneak in the sort of logic used in creationism were legitimate criteria.

Whenever it was my turn, I promptly proposed a legitimate criterion. When it was your turn, you tried to sneak in stuff like a requirement that in order to be scientific, a paper had to acknowledge all alternate theories. There's no scientific reason for that rule; it's merely a tactic used by creationists to try to get their creationist theories mentioned in scientific publications.

Let's have more honesty and less rhetorical squirming from you, Max.

[mdettweiler]

Originally Posted by cheesehead

That question has already been answered by the estimates presented earlier.

Your claim that "how much actual temperature increase is going to be caused by global warming" is "the real question" that I haven't yet answered is only a rhetorical strawman device.

Speaking of unanswered questions, why do you keep dodging the questions I've put to you? Let's see some answers from your side!

Bull.

This is just a pretense that I've dodged something, whereas the truth is that you're the one who hasn't answered important questions I've posed in this thread.

If you spent less time composing rhetorical trickery and more time giving us straight answers to straight questions, you'd be more respected.

You could convince me of your position ... if you'd present actual evidence to support your claims. But you don't, despite my repeatedly reminding you of that lack.

Instead of presenting evidence, you present only rhetoric. You are an intellectual coward. (I'm qualified to make that accusation because I behaved that way in certain situations when I was younger, so I recognize it when you do it now.)

Yes, it did, didn't it?

I requested that you present legitimate criteria for distinguishing science from non-science, but you kept trying to pretend that thinly-disguised attempts to sneak in the sort of logic used in creationism were legitimate criteria.

Whenever it was my turn, I promptly proposed a legitimate criterion. When it was your turn, you tried to sneak in stuff like a requirement that in order to be scientific, a paper had to acknowledge all alternate theories. There's no scientific reason for that rule; it's merely a tactic used by creationists to try to get their creationist theories mentioned in scientific publications.

Let's have more honesty and less rhetorical squirming from you, Max.

Cheesehead, I really do not have the time to continue this discussion now. I realized that you'd probably see it as dodging, though I guess that's somewhat unavoidable.

I do intend to get back to the science/anti-science debate at some point in the future. I have been collecting evidence and refining my position since we last discussed that, and should have something sufficiently non-squirmy next time.

I'd also love to debate the fine points of rhetoric vs. evidence and their places in scientific discussion later on. I just don't have the time to spare to do it now, okay?

[xilman]

http://news.bbc.co.uk/1/hi/sci/tech/8437703.stm

I make no statement as to whether this is AGW or not. It appears to me that it will lead to GW, but I'm just a simple chemist so what do I know?


Paul